Question: In chemistry class, the girl to boy ratio is $7$ to $7$. If there are $35$ girls, how many boys are there?
Solution: A ratio of $7$ girls to $7$ boys means that there is a group of $7$ girls for every group of $7$ boys. If there are $35$ girls, then there are $5$ groups of $7$ girls each. Because we know the ratio is $7:7$ , there must be $5$ groups of $7$ boys each. There is a total of $35$ boys in chemistry class.